Ken Livingstone burst into tears today as he viewed a screening of his party election broadcast.

The Labour candidate started crying as he watched a series of “ ordinary” Londoners saying why they wanted him as Mayor.

In bizarre scenes, party leader Ed Miliband comforted the 66-year-old ex-mayor by leaning forward and patting him on the back.

Mr Livingstone released a YouTube clip of Londoners appealing for him to “win back” the city on their behalf.

As the official broadcast was released today Mr Livingstone said he had been overcome by the responsibility of running the capital.

He said the film was “a tear jerker”, adding: “It’s an appalling responsibility. The people you saw on the screen represent hundreds of thousands of Londoners who desperately want a mayor who is going to make their life easier in this city.

“It’s a huge responsibility to make people’s lives better over the next four years and that’s why I want to win.”

Mr Miliband, who was at his candidate’s manifesto launch, added: “It was a very powerful broadcast and expressed the central message of our campaign.”

The last time Mr Livingstone cried in public was when he apologised for the slave trade during his time at City Hall.

He said: “I feel a responsibility at this election. If I win, I know that millions of lives will be better.”

The broadcast, which was introduced by Mr Livingstone, featured a series of Londoners from all walks of life stating why they wanted him to be Mayor.

Is was directed by Johnny Maginn from Mustard Films and produced by ad agency BETC.

Labour sources said that all the people in the broadcast, which goes out today, were Labour supporters and only one - a Jewish man - was a former councillor. It was unclear how much the film cost to make.

Mr Livingstone also attempted to draw a line under the tax row which has so badly dented his trust ratings.